As usual, I could use up a mole of electrons describing them, but one in particular caught my eye:

Egads! Click it to embiggen.
This shows a swath of sky in the (northern hemisphere) summer constellation of Aquila, the Eagle. Aquila lies in the plane of the Milky Way galaxy, and when you look in that direction what you see is a mess of gas clouds littered with dust, and it just so happens a lot of this junk is busily forming stars. Herschel is sensitive to the far infrared, way outside what our eyes can see, so to its eye this region is aglow with warm dust and star birth.

But take a look at the blue structure at the lower left, the part shaped like a slightly tilted U. As soon as I saw it, I knew what it was: a blowout.

When stars form, they tend to start up a wind of material blowing off their surface, like a solar wind dialed up to 11. If these stars are inside a dense cloud they’ll plow up the surrounding material, creating a cavity. If they’re near the edge of that cloud, one side of the cavity will pop, creating a blowout. That’s what you’re seeing here: a pile of stars announcing their presence to the universe by kicking a hole in the wall of their nursery.

I remember my own daughter wailing and kicking in the minutes after she was born. When a baby has a mass measuring in the octillions of tons, its kick is somewhat more substantial.

If not, do you get dibs on “christening” it? Shame its just a day too late for Mothers Day.

@ 3. Astrofiend Says:

Wow. My new favourite scope just keeps delivering the jaw-droppers…

Do you mean WISE then? ( http://wise.ssl.berkeley.edu/ ) That’s my new fave since I saw it launched (Thanks NASA-TV online) one hundred & forty six days twenty- three hours and twenty -three minutes ago. Seriously. But Herschel is up there as well as is the Solar Dynamics Observatory – it’s too hard to choose any one favourite really. Plus my old fave scope – Hubble – ain’t doing so badly either. (Nor are Fermi & Spitzer.)

What are the reasons why we don’t see anything like this in the sky with the naked eye?

Do we just happen by chance to be too far away from all the big beautiful nebulae for them to be visible without a telescope? (If so, how far would we have to travel to see one? How far apart are they, on average?)

Are they too dim to see? Or in the wrong wavelengths? Is there some other reason?

As a conservative guess, I’m pretty sure you did. Between the electron flow required to process the typing instructions to your fingers, the interaction between your keyboard, CPU, hard drive, intertubes, and my computer, I’d say at least a mole of electrons were involved in the transmission of information from your brain to mine.

Too dim and wrong wavelengths, and in some cases too small (from our vantage point).

Even if they were the right wavelengths they would likely be far less dramatic to the naked eye, since our color vision doesn’t work well for dim objects. Unless we were close enough to them so they were daylight-bright, but it wouldn’t be too healthy to be that close to an active star-forming region.

In fact, many nebulae are so rarified that it wouldn’t matter whether you were close or not — if you’re far away, they’re dim because, well, they’re far away, but if you’re close they’re still dim because they’re so diffuse.

Does anyone know what the artifact at about -4.5, 15.5 is? It looks like a mirror mount, but I’m really out of the loop on this sort of thing. Is this what “lens flare” looks like on a giant Newtonian in space?

Why was the first thing I thought of, that this is a picture of Dark Phoenix grabbing the star D’Bari and making it go supernova in X-Men 135? I hope Jean Gray was not really wiping out a planet of intelligent, peaceful bipeds. If she did, I want the Shi’ar here PRONTO!

OTOH, at least one star – Gamma Orionis or Bellatrix – has a name that designates it as specifically female as the name means “female warrior.” (Which made it an apt choice for J.K. Rowling to use in the Harry Potter series.) See : http://stars.astro.illinois.edu/sow/bellatrix.html